In the last six months, we've seen uploads from mobile phones to YouTube jump 1700%; just since last Friday, when the iPhone 3GS came out, uploads increased by 400% a day.

This growth represents three things coming together: new video-enabled phones on the market, improvements to the upload flow when you post a video to YouTube from your phone, and a new feature on YouTube that allows your videos to be quickly and effortlessly shared through your social networks. It takes just a minute to connect your YouTube account to your Facebook, Twitter and Google Reader accounts. Complete a simple, one-time connection on our upload page to allow all your friends and followers to get a real-time stream of your uploads to YouTube, which can be essential in this age of citizen reporting and ubiquitous sharing.

Can you make your test video go viral through your social networks? If you can, we're willing to feature that video on our homepage. Upload a video from your phone, tag it with "mobiletest," share it with your social network, and Tweet us the link (so be sure to put "@youtube" and "mobiletest" in your message). We'll give you one week to spread your test video far and wide, after which we'll take a look at the most popular clips and feature a few on our homepage in a special "mobile upload" edition of our Spotlight Video.

So get goin', and if you want more info about playing and creating YouTube videos on your phone, go to http://www.youtube.com/mobile. There's a video on that page (or click here) that offers a step-by-step guide to uploading videos from your phone.